When a system designer specifies a nonisolated dc/dc powermodule, considering the needed input voltage range isequally as important as considering the required performanceattributes and features. Generally, nonisolated moduleshave either a narrow or a wide input voltage range. Narrowinputmodules typically have a nominal input voltage of3.3, 5, or 12 V. For systems that operate from a tightlyregulated input bus—such as those that do not use batterybackup—a narrow-input module is often adequate sincethe input remains fairly stable.Offering greater flexibility, wide-input modules operatewithin a range of 7 to 36 V, which includes the popular12- or 24-V industrial bus. This enables a single module tobe used for generating multiple voltages. These modulesare ideal for industrial controls, HVAC systems, vehicles,medical instrumentation, and other applications that usea loosely regulated Distribution bus. In addition, systemspowered by a rectifier/battery charger with lead-acidbattery backup almost always require wide-input modules.System designers who choose power supplies may wantto take a close look at the latest generation of wide-inputdc/dc modules.
标签： Wide-input modules offer dc
上传时间： 2014-12-24
上传用户：dragonhaixm
This white paper discusses how market trends, the need for increased productivity, and new legislation have accelerated the use of safety systems in industrial machinery. This TÜV-qualified FPGA design methodology is changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to market. This allows FPGA users to design their own customized safety controllers and provides a significant competitive advantage over traditional microcontroller or ASIC-based designs. Introduction The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas around machines such as fast-moving robots, and distributed control systems in process automation equipment such as those used in petrochemical plants. The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was developed in the mid-1980s and has been revised several times to cover the technical advances in various industries. In addition, derivative standards have been developed for specific markets and applications that prescribe the particular requirements on functional safety systems in these industry applications. Example applications include process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC 62304), automotive (ISO 26262), power generation, Distribution, and transportation. 图Figure 1. Local Safety System
上传时间： 2013-11-05
上传用户：维子哥哥
EPON主要由三个部分构成，包括光线路终端(OLlj Optical Line Terminal)、光分配网络(ODN，Optical Distribution Network)和光网络单元(ONU，Optical Network Unit .
上传时间： 2013-11-11
上传用户：JGR2013
This white paper discusses how market trends, the need for increased productivity, and new legislation have accelerated the use of safety systems in industrial machinery. This TÜV-qualified FPGA design methodology is changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to market. This allows FPGA users to design their own customized safety controllers and provides a significant competitive advantage over traditional microcontroller or ASIC-based designs. Introduction The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas around machines such as fast-moving robots, and distributed control systems in process automation equipment such as those used in petrochemical plants. The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was developed in the mid-1980s and has been revised several times to cover the technical advances in various industries. In addition, derivative standards have been developed for specific markets and applications that prescribe the particular requirements on functional safety systems in these industry applications. Example applications include process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC 62304), automotive (ISO 26262), power generation, Distribution, and transportation. 图Figure 1. Local Safety System
上传时间： 2013-11-14
上传用户：zoudejile
Calculation of the Differential Impedance of Tracks on FR4 substrates There is a discrepancy between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary Element field methods, show that the Distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
上传时间： 2013-10-18
上传用户：masochism
CSL is a programming language with C syntax and comprehensive libraries. The compact scripting engine can also be embedded into your own applications as a powerful macro language. Windows Distribution utilities.
标签： comprehensive programming libraries scripting
上传时间： 2013-11-27
上传用户：xuanchangri
Filename: main.c * Description: A simple test program for the CRC implementations. * Notes: To test a different CRC standard, modify crc.h. * * * Copyright (c) 2000 by Michael Barr. This software is placed into * the public domain and may be used for any purpose. However, this * notice must not be changed or removed and no warranty is either * expressed or implied by its publication or Distribution.
标签： test implementations Description Filename
上传时间： 2015-02-02
上传用户：leehom61
The Point-to-Point Protocol (PPP) for the Transmission of Multi-protocol Datagrams over Point-to-Point Links Status of this Memo This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.
标签： Point-to-Point Multi-protocol Transmission Datagrams
上传时间： 2014-01-22
上传用户：cazjing
RFC1661 PPP协议 （RFC1661 The Point-to-Point Protocol (PPP)） 本备忘录状态 This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
标签： 1661 Point-to-Point informatio RFC
上传时间： 2014-12-07
上传用户：569342831
如果您刚接触嵌入式开发，那么大量可用的引导装载程序（bootloader）、规模缩小的分发版（Distribution）、文件系统和 GUI 看起来可能太多了。但是这些丰富的选项实际上是一种恩赐，允许您调整开发或用户环境以完全符合您的需要。这篇Linux 嵌入式开发的概述将帮助您理解所有这些选项
标签： 嵌入式开发
上传时间： 2014-01-25
上传用户：wanghui2438
